A detailed study reveals that RBMY1A1-dependent sorting of miR-105-5p into fibroblasts and subsequent internalization of miR-105-5p promote the transformation of NFs to CAFs by downregulating LATS2 expression and activating NF-κB signaling, which concurrently facilitates the EMT of breast cancer cells. The gene discussed is NFKB1; the disease is breast cancer.